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Effects of residual motion compensation errors on the performance of airborne along-track interferometric SAR

Frontiers of information technology & Electronic Engineering 2016年第10期17卷 1095-1105页

作者： Hui ZHANG Jun HONG Xiao-lan QIU Ji-chuan LI Fang-fang LI Feng MING Institute of Electronics Chinese Academy of Sciences Beoing 100190 China University of the Chinese Academy of Sciences Beijing 100190 China Key Laboratory of Technology in Geo-spatial Information Processing and Application Systems Beijing 100190 China Science and Technology on Millimeter-Wave Laboratory Beijing 100854 China

Two approximations, center-beam approximation and reference digital elevation model （DEM） approximation, are used in synthetic aperture radar （SAR） motion compensation procedures. They usually introduce residual motion compensation errors for airborne single-antenna SAR imaging and SAR interferometry. In this paper, we investigate the effects of residual uncompensated motion errors, which are caused by the above two approximations, on the performance of airborne along-track interferometric SAR （ATI-SAR）. The residual uncompensated errors caused by center-beam approximation in the absence and in the presence of elevation errors are derived, respectively. Airborne simulation parameters are used to verify the correctness of the analysis and to show the impacts of residual uncompensated errors on the interferometric phase errors for ATI-SAR. It is shown that the interferometric phase errors caused by the center-beam approximation with an accurate DEM could be neglected, while the interferometric phase errors caused by the center-beam approximation with an inaccurate DEM cannot be neglected when the elevation errors exceed a threshold. This research provides theoretical bases for the error source analysis and signal processing of airborne ATI-SAR.

关键词： Synthetic aperture radar （SAR） Along-track interferometric Motion compensation Residual error Interferometric phase

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Planar near-field to far-field transformation for massive MIMO systems 34

Planar near-field to far-field transformation for massive MI...

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第三十四届中国控制会议

作者： HAN Xiangzi TAN Xiaobin WU Fan CAS Key laboratory of Technology in Geo-spatial Information Processing and Application System School of Information Science and Technology University of Science and Technology of China

ISBN: (纸本)9781467374439

The massive or large scaled multiple input multiple output(MIMO) systems have gained huge consideration due to high achievable data rates, reliable system performance and advantaged energy efficiency for future wireless networks. For such systems, we should have a keen knowledge of the channel model, the ways of configuration, spectral efficiency and so on. The obtaining of the far-field pattern in the massive MIMO system from measurements made in the near-field has attracted widespread attention recently. In this article, two basic techniques for accomplishing this have been proposed. In the first technique, the NTFF(near-field to far-field) transformation is based on the equivalence principle. While in the second technique, it is based on the plane wave spectrum(PWS) expansion. Both of the methods have their own advantages for the massive MIMO systems. One can drastically reduce the computation time and the other can make enormous reduction in the storage consumption. Experimental results show that the two transformation techniques are proved to be feasible and they are consistent with each other.

关键词： massive MIMO,NTFF transformation,the equivalence principle,PWS expansion

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The shadow enhancement for targets with flat structures in SAR images

The shadow enhancement for targets with flat structures in S...

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IEEE International Symposium on geoscience and Remote Sensing (IGARSS)

作者： Yueting Zhang Xiaolan Qiu Bin Lei Kun Fu Fangfang Li Chibiao Ding Key Laboratory of Geo-spatial Information Processing and Application System Technology Chinese Academy of Sciences Institute of Electronics Chinese Academy of Science

The edges of the shadow region are blurred in the SAR image due to the moving of the radar during data collection. This phenomenon becomes obvious in the High Resolution SAR images. Shadow enhancement is of great value for ATR especially when the scattering centers of the target itself are not clear. In this paper, an approach for shadow enhancement in the SAR images for targets with plat structures is presented. And experiments on the Mini-SAR data test the validity of the approach.

关键词： Synthetic aperture radar Scattering Azimuth Image edge detection Automotive components Radar imaging

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Circuit tolerance design by differential evolution with hybrid analysis method

Circuit tolerance design by differential evolution with hybr...

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International Workshop on Advanced Computational Intelligence (IWACI)

作者： Fugui Zhong Bin Li Bo Yuan CAS Key Laboratory of Technology in Geo-spatial Information Processing and Application Systems University of Science and Technology of China Hefei China CAS Key Laboratory of Technology in Geo-spatial Information Processing and Application Systems USTC-Birmingham Joint Research Institute in Intelligent Computation and Its Applications (UBRI) University of Science and Technology of China Hefei China USTC-Birmingham Joint Research Institute in Intelligent Computation and Its Applications (UBRI) University of Science and Technology of China Hefei China

With the continued scaling down of electronic device dimensions, circuit design under parameter variations has received increasing interests. In this paper, a new method that combine the differential evolution with hybrid analysis method is presented to solve the worst-case circuit tolerance design problem. The hybrid analysis method is comprised of two commonly used worst-case circuit tolerance analysis approaches, vertex analysis and Monte Carlo analysis. The search direction of differential evolution is leaded by vertex analysis at the first stage, through which we can reduce the computational complexity of fitness calculation dramatically. Monte Carlo analysis, a higher accuracy analysis method, is applied to ensure the quality of the solutions at the second stage. Some of the individuals are reinitialized to enhance the diversity of the population at the beginning of the second stage. By cooperating the two analysis methods, the proposed method can converge to the global optimum or near-optimum solutions more quickly. The experiment results show the effectiveness and efficiency of proposed techniques for the circuit tolerance design.

关键词： Monte Carlo methods Algorithm design and analysis Sociology Uncertainty Upper bound Computational efficiency

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A general law of human mobility

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Science China(information Sciences) 2015年第10期58卷 24-37页

作者： LIANG Xiao ZHAO JiChang XU Ke Key Laboratory of Technology in Geo-spatial Information Processing and Application System Institute of Electronics Chinese Academy of Sciences School of Economics and Management Beihang University State Key Laboratory of Software Development Environment Beihang University

The intrinsic factors that drive human mobility have remained unclear for decades. Our observations from both intra-urban and inter-urban trips demonstrate a general law of human mobility. Specifically, the probability that a trip will occur is inversely proportional to the size of population located inside a circle with radius equal to the travel distance centered at the trip origin. A simple parameterless rank-based model is presented; this model can predict human flows with a convincing fidelity. Moreover, existing models can be implemented as special cases of our model, suggesting that our model is stable at more spatial scales. Our model also creates a fundamental bridge between individual mobility and social relationships.

关键词： human mobility social mobility general law rank-based model flux prediction

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Improved rate-distortion optimization algorithms for hevc lossless coding 21

Improved rate-distortion optimization algorithms for hevc lo...

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21st International Conference on MultiMedia Modeling, MMM 2015

作者： Chen, Fangdong Li, Houqiang CAS Key Laboratory of Technology in Geo-spatial Information Processing and Application System University of Science and Technology of China Hefei China

ISBN: (纸本)9783319144443

To avoid distortion, the quantization is not implemented on residues for lossless mode in HEVC. As a result, the conventional lambda model in Rate-Distortion Optimization (RDO), where lambda is related to the quantization parameter (QP), is unreasonable for lossless coding. This paper first demonstrates the role that lambda value plays in the rough RDO of HEVC lossless coding, and a Simulated Annealing algorithm based approach is proposed to obtain the most appropriate lambda for each largest coding unit. Considering the computational complexity, the other simplified method using least square errors prediction is proposed to improve the rough RDO process. Experimental results reveal that on top of the lossless coding mode, the improved method offers the performance with a 1.0%, 1.3% and 1.1% bit-rate reduction on average for Random-access Main, Low-delay B Main and Low-delay P Main configurations, respectively, while brings negligible increases of computational complexity in the encoder. © Springer International Publishing Switzerland 2015.

关键词： Computational complexity

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Automated ortho-rectified SAR image of GF-3 satellite using Reverse-Range-Doppler method

Automated ortho-rectified SAR image of GF-3 satellite using ...

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IEEE International Symposium on geoscience and Remote Sensing (IGARSS)

作者： Jiayin Liu Xiaolan Qiu Wen Hong Institute of Electronics Chinese Academy of Sciences Beijing China Key Laboratory of Technology on Geo-spatial Information Processing and Application System Chinese Academy of Sciences Beijing China National Key Laboratory of Microwave Imaging Technology Beijing China

GF-3 is the Chinese Synthetic Aperture Radar (SAR) satellite mission with scientific and commercial applications, which will be launched in 2016. The ortho-rectification image combined with the DEM data can only be satisfied with the applications of the high resolution radar image, the data quantity with wide-breadth also put forward higher request to the automation processing. The Reverse-Range-Doppler method was used to ortho-rectified the SAR image of GF-3 satellite based on the Range-Doppler model in this paper. It not only ensures the correction precision, but also simplifies the iteration steps about DEM data, and improves the efficiency of automatic processing.

关键词： Synthetic aperture radar Mathematical model Satellites Doppler effect Space vehicles Earth Azimuth

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Consistency analysis of the approximate discrete-time model for stochastic nonlinear systems with Markovian switching

Consistency analysis of the approximate discrete-time model ...

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Youth Academic Annual Conference of Chinese Association of Automation (YAC)

作者： Peilong Yu Yu Kang Xinxin Fu Department of Automation University of Science and Technology of China Hefei China Department of Automation and State Key Laboratory of Fire Science University of Science and Technology of China Hefei China Chinese Academy of Sciences Key Laboratory of Technology in Geo-Spatial Information Processing and Application System Beijing China

ISBN: (纸本)9781509044245

In this paper, we mainly study the approximate discrete-time model for stochastic nonlinear systems with Markovian switching (SNSwMS). The consistency condition between the approximate discrete-time model and the exact discrete-time model of systems is discussed and analyzed. Then, the quantitative relationship between the bound of the model error in mean square and the initial value and sampling period is obtained.

关键词： Decision support systems Zirconium Switches Analytical models Databases Optimal control

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Exponential synchronization of partial-state coupled linear systems via contraction analysis

Exponential synchronization of partial-state coupled linear ...

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Annual Conference of Industrial Electronics Society

作者： Qichao Ma Ku Du Yu Kang Wei Xing Zheng Jiahu Qin Department of Automation University of Science and Technology of China Hefei China Department of Automation Key Laboratory of Technology in Geo-Spatial Information Processing and Application Systems Beijing China Engineering and Mathematics Western Sydney University Sydney NSW Australia

In this paper, the contraction theory is used to analyze the synchronization for a collection of partial-state linearly coupled linear systems. First, the synchronization problem of the linear systems is transformed by defining proper error variables such that a stability problem of error systems is to be investigated. Then, the contraction analysis is performed with respect to the error system dynamics. It turns out that the error system dynamics is contracting, which in turn proves that the original systems reach synchronization exponentially fast. In addition, a brief comparison between Lyapunov method and contraction analysis is also provided. Finally, two examples are presented in order to illustrate the effectiveness of the theoretical result.

关键词： Synchronization Linear systems Trajectory Eigenvalues and eigenfunctions Symmetric matrices Lyapunov methods

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A new method for attitude refinement of earth observation satellite with asynchronous images

A new method for attitude refinement of earth observation sa...

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IEEE International Symposium on geoscience and Remote Sensing (IGARSS)

作者： Tao Sun Li Huang Hui Long Bao-Cheng Liu Key Laboratory of Technology in Geo-spatial Information Processing and Application System Chinese Academy of Sciences Beijing P. R. China TH-Centre of China Beijing P. R. China

The accuracy of attitude observation is always the main contributor to geometric performance of earth observation satellites (EOSs). Given the ground process requirement, linear pushbroom and asynchronous imaging sensors are widely used in EOSs, such as multispectral sensor with sequential line arrays, three-line array sensor in stereo mapping satellite, panchromatic sensor with multiple non-collinear CCD chip in some high-resolution optical satellite. By using the images of those sensors, this paper proposes a method, which is based on image registration approach, rigorous forward intersection and bundle adjustment technology, to refine attitude data of satellite for improving geometric performance of images. Preliminary experiments, which used multi-sensors asynchronous images of Chinese Mapping Satellite-1-02, demonstrate that the proposed method is capable of improving internally coincident precision of attitude data without ground control points. In particular, relative positioning accuracy of images can be directly improved, and absolute positioning accuracy can consequently be improved via additionally using a few GCPs in the stripe image data.

关键词： Satellites Sensor arrays Calibration Mathematical model Remote sensing Image sensors

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